Percorrer por autor "Adega, Filomena"
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- Anti-hepatocellular carcinoma activity using human HepG2 cells and hepatotoxicity of 6-substituted methyl 3-aminothieno[3,2-b]pyridine-2- carboxylate derivatives: In vitro evaluation, cell cycle analysis and QSAR studiesPublication . Abreu, Rui M.V.; Ferreira, Isabel C.F.R.; Calhelha, Ricardo C.; Lima, Raquel T.; Vasconcelos, M. Helena; Adega, Filomena; Chaves, Raquel; Queiroz, Maria João R.P.Hepatocellular carcinoma (HCC) is a highly complex cancer, resistant to commonly used treatments and new therapeutic agents are urgently needed. A total of thirty-two thieno[3,2-b]pyridine derivatives of two series: methyl 3-amino- -(hetero)arylthieno[3,2-b]pyridine-2-carboxylates (1ae1t) and methyl 3-amino-6-[(hetero)arylethynyl]thieno[3,2-b]pyridine-2-carboxylates (2ae2n), previously prepared by some of us, were evaluated as new potential anti-HCC agents by studying their in vitro cell growth inhibition on human HepG2 cells and hepatotoxicity using a porcine liver primary cell culture (PLP1). The presence of amino groups linked to a benzene moiety emerges as the key element for the anti-HCC activity. The methyl 3-amino-6-[(3-aminophenyl)ethynyl]thieno[3,2-b]pyridine-2-carboxylate (2f) is the most potent compound presenting GI50 values on HepG2 cells of 1.2 mM compared to 2.9 mM of the positive control ellipticine, with no observed hepatotoxicity (PLP1 GI50 > 125 mM against 3.3 mM of ellipticine). Moreover this compound changes the cell cycle profile of the HepG2 cells, causing a decrease in the % of cells in the S phase and a cell cycle arrest in the G2/M phase. QSAR studies were also performed and the correlations obtained using molecular and 1D descriptors revealed the importance of the presence of amino groups and hydrogen bond donors for anti-HCC activity, and hydrogen bond acceptors for hepatotoxicity. The best correlations were obtained with 3D descriptors belonging to different subcategories for anti-HCC activity and hepatotoxicity, respectively. These results point to different molecular mechanisms of action of the compounds in anti-HCC activity and hepatotoxicity. This work presents some promising thieno[3,2-b]pyridine derivatives for potential use in the therapy of HCC. These compounds can also be used as scaffolds for further synthesis of more potent analogs.
- Anti-proliferative activity of thieno[3,2-b]pyridine derivatives in tumoral and primary hepatic cell lines.Publication . Abreu, Rui M.V.; Queiroz, Maria João R.P.; Ferreira, Isabel C.F.R.; Adega, Filomena; Chaves, Raquel
- Antioxidant and anti-inflammatory properties of red, white and pink globe amaranth hydromethanolic extractsPublication . Liberal, Ângela; Pereira, Carla; Calhelha, Ricardo C.; Abreu, Rui M.V.; Adega, Filomena; Ferreira, Isabel C.F.R.Medicinal plants have been playing a vital role on human health and healing, representing one of the major sources of drugs in modem and traditional medicine [1]. Plants synthesize and preserve a variety of biochemical products that can be used as pharmaceutical compounds [2], and recently there has been an increasing interest in the therapeutic potential of plants as antioxidants and anti-inflammatories [3]. Oxidative stress and inflammation play critical roles in the pathogenesis of many diseases, such as cancer, cardiovascular disease, arthritis and obesity [4], among others. Thus, the aim of this study was to explore the bioactivity of red, white and pink globe amaranth (different cultivars of Gomphrena globosa L.) hydromethanolic extracts, namely the antioxidant and anti-inflammatory activities. The antioxidant activity was tested through radicals scavenging capacity, reducing power, and lipid peroxidation inhibition, whereas the anti-inflammatory activity was assessed by monitoring the inhibition of nitric oxide (NO) release in the mouse macrophage-like cell line RAW 264.7. The absence of toxicity of the extracts was also confirmed by the sulphorodamine B (SRB) assay applied to a porcine liver primary culture (PLP2) established by the authors. Among the three studied samples, pink globe amaranth showed the highest antioxidant activity, with the lowest ECso values (0.25 to 1.02 mg/mL), followed by red (0.41 to 1.30 mg/mL) and white (0.57 to 1.47 mg/mL) globe amaranth. Regarding the anti-inflammatory activity, pink and red globe amaranth also revealed the lowest ECso values (133 and 136 pg/mL, respectively), with white globe amaranth revealing an ECso value of 198pg/mL. None of the extracts presented cytotoxicity in PLP2 cells up to 400 pg/mL. From the results obtained, we can conclude that the extracts of these plants can be considered good sources of antioxidants and can also be used for anti-inflammatory purposes.
- A comparison of the bioactivity and phytochemical profile of three different cultivars of globe amaranth: red, white, and pinkPublication . Liberal, Ângela; Calhelha, Ricardo C.; Pereira, Carla; Adega, Filomena; Barros, Lillian; Dueñas, Montserrat; Santos-Buelga, Celestino; Abreu, Rui M.V.; Ferreira, Isabel C.F.R.The phytochemical profiles and bioactivities of red, white and pink globe amaranth (Gomphrena haageana K., Gomphrena globosa var. albiflora and Gomphrena sp., respectively), much less studied than the purple species (G. globosa L.), were compared. The chemical characterization of the samples included the analysis of macronutrients and individual profiles of sugars, organic acids, fatty acids, tocopherols, and phenolic compounds. Their bioactivity was evaluated by determining the antioxidant and anti-inflammatory activities; the absence of cytotoxicity was also determined. Red and pink samples showed the highest sugar content. Otherwise, the white sample gave the highest level of organic acids, and together with the pink one showed the highest tocopherol and PUFA levels. Quercetin-3-O-rutinoside was the major flavonol in white and pink samples, whereas a tetrahydroxy-methylenedioxyflavone was the major compound in the red variety, which revealed a different phenolic profile. The pink globe amaranth hydromethanolic extract revealed the highest antioxidant activity, followed by those of red and white samples. The anti-inflammatory activity was more relevant in red and pink varieties. None of the samples presented toxicity in liver cells. Overall, these samples can be used in bioactive formulations against inflammatory processes and in free radical production.
- New potential anti-hepatocellular carcinoma (HCC) agents: in vitro evaluation of anti-HCC activity and hepatotoxicity of 6-substituted methyl 3-aminothieno[3,2-b]pyridine-2-carboxylates and QSAR studiesPublication . Abreu, Rui M.V.; Queiroz, Maria João R.P.; Ferreira, Isabel C.F.R.; Calhelha, Ricardo C.; Adega, Filomena; Chaves, RaquelHepatocellular carcinoma (HCC) is a major health problem with more than 660,000 new cases per year worldwide [1]. HCC is resistant to commonly used treatments like chemotherapy and radiotherapy and new anti-HCC therapies are urgently needed. Sorafenib was the first approved small molecule against HCC and underlines the importance of identifying potential new anti-HCC drugs [2]. Thirty-two 6-substituted methyl 3-aminothieno[3,2-b]pyridine-2-carboxylates, previously prepared by some of us [3,4], were evaluated as potential new anti-HCC agents by studying their in vitro cell growth inhibition on human HepG2 cells, generally regarded as a good HCC model, and hepatotoxicity using a porcine liver primary cell culture (PLP1). The presence of amino groups linked to a benzene moiety on the substituent of the 6-position emerged as the key element for the anti-HCC activity.
- Tocopherols as bioactive compounds in different cultivars of Gomphrena globosa L.Publication . Liberal, Ângela; Pereira, Carla; Adega, Filomena; Barros, Lillian; Ferreira, Isabel C.F.R.Tocopherols are lipid-soluble molecules that belong to the group of the Vitamin E compounds, playing an essential role on human nutrition and health [1]. The term "Vitamin E" was first introduced as an important dietary factor for animal reproduction and, more than 40 years later, it was associated to antioxidant properties. Nowadays, most of the researches focus on the fundamental chemistry that explains their antioxidant properties, specific location, role in biological membranes, and particularity on the benefits of these compounds for human health [1]. The antioxidant activity of tocopherols can be explained by two main mechanisms: first as scavengers of lipid peroxyl radicals, produced from polyunsaturated fatty adds of the membrane phospholipids and lipoproteins, through the transfer of a hydrogen atom; and second as a singlet molecular oxygen quencher, which can oxidize membrane lipids, proteins, amino acids, and nucleic acids, among others [2, 3]. In this context, our study focused on the identification and quantification of tocopherols in three different Gomphrena globosa L. cultivars (red, white and pink globe amaranth). The analysis was performed by HPLC and the quantification was based on their fluorescence signal response. White and pink globe amaranth revealed similar amounts of Υ-tocopherol (1. 04 and 1.09 mg/100 g of dry weight) and total tocopherols (1. 37 and 1.38 mg/100 g, respectively). α-Tocopherol was found in higher concentrations in red globe amaranth (0.55 mg/100 g), that also presented Υ-tocopherol (0. 50 mg/100 g), but this was the only sample where α-tocopherol was not detected. This latter isoform was found in low amounts in the other two cultivars in concentrations ranging from 0. 05 to 0.06 mg/100 g (for white and pink globe amaranth, respectively). The results obtained offer prospects for the use of these less studied cultivars of G. globosa as antioxidants, making them suitable to be included in the human diet.